| go east: phylogeographies of mauremys caspica and m. rivulata- discordance of morphology, mitochondrial and nuclear genomic markers and rare hybridization. | in recent years many cases of hybridization and introgression became known for chelonians, requiring a better understanding of their speciation mechanisms. phylogeographic investigations offer basic data for this challenge. we use the sister species mauremys caspica and m. rivulata, the most abundant terrapins in the near and middle east and south-east europe, as model. their phylogeographies provide evidence that speciation of chelonians fits the allopatric speciation model, with both species b ... | 2008 | 18179513 |
| a light and electron microscopic study of the epithelium of the extrapulmonary airways of mauremys caspica and lacerta lepida (reptilia). | the epithelium of the extrapulmonary airways of a chelonia (mauremys caspica) and a squamata (lacerta lepida) was investigated by means of conventional light and transmission electron microscopy, scanning electron microscopy, histochemistry and immunocytochemistry. the epithelium of mauremys caspica is composed of basal, ciliated, endocrine and mucous cells. serotonin-immunoreactivity was detected in the endocrine cells. mucous cells were found to contain either sialo-mucins or both sialo- and s ... | 2012 | 3370620 |
| chemical contaminants and their effects in fish and wildlife from the industrial zone of sumgayit, republic of azerbaijan. | sediment from a wetland adjacent to an industrial wastewater treatment plant in sumgayit contained concentrations of total pahs, total pcbs, aldrin, biphenyl, chlordane, ddt, mercury, beta-endosulfan, heptachlor, alpha-hexacyclohexane (alpha-hch), gamma-hch, and several individual pah congeners that were elevated relative to published sediment quality guidelines. chemical analyses of tissues from european pond turtles (emys orbicularis) had increased levels of many of the same chemicals includin ... | 2003 | 14680332 |
| dynamic changes in the receptive fields of l1-type horizontal cells in the retina of the turtle mauremys caspica. | the resistances of the horizontal cell syncytium in the vertebrate retina are modulated in a time-dependent fashion during light stimulation. therefore, the spatial properties of horizontal cells are expected to change with time after the illumination conditions are altered. this study was designed to investigate time- and intensity-dependent changes in the receptive-field properties of l1-type horizontal cells in the turtle mauremys caspica. photoresponses were elicited by monochromatic (650 nm ... | 2002 | 12507328 |
| spatial-chromatic interactions in c-type horizontal cells of the turtle (mauremys caspica) retina. | horizontal cells are second-order retinal neurons that play a key role in spatial information processing. in some cold-blooded vertebrates such as turtles, a subtype of these cells, the chromaticity horizontal cells exhibit color-opponent responses and therefore are considered to be important also for color information processing. to reveal spatial and color interactions, the receptive-field properties of red/green and yellow/blue chromaticity horizontal cells in the retina of the turtle mauremy ... | 2002 | 12180861 |
| immunocytochemical localization of corticotropin-releasing factor in the brain of the turtle, mauremys caspica. | brain sections of the turtle, mauremys caspica were studied by means of an antiserum against rat corticotropin-releasing factor. immunoreactive neurons were identified in telencephalic, diencephalic and mesencephalic areas such as the cortex, nucleus caudatus, nucleus accumbens, amygdala, subfornical organ, paraventricular nucleus, hypothalamic dorsolateral aggregation, nucleus of the paraventricular organ, infundibular nucleus, pretectal nucleus, periventricular grey, reticular formation and nu ... | 1993 | 8214631 |
| vascular and leptomeningeal projections of the subcommissural organ in reptiles. lectin-histochemical, immunocytochemical, and ultrastructural studies. | in the snake, natrix maura, and the turtle, mauremys caspica, the basal processes of the ependymal cells of the subcommissural organ project toward the local blood vessels and the leptomeninges. these processes and their endings were studied using aldehyde-fuchsin (af), periodic-acid schiff (pas), periodic-acid silver-methenamine (pa-sm), concanavalin a (cona), wheat germ agglutinin (wga), immunoperoxidase staining (employing an antiserum against bovine reissner's fiber; afru), and conventional ... | 1987 | 3692928 |
| seasonal variations in the immune response of the tortoise mauremys caspica. | the primary and secondary immune responses to sheep erythrocytes (srbc) have been characterized in the tortoise mauremys caspica in terms of circulating antibodies and pfc response in two different seasons: summer and autumn. primary immunization is followed by the appearance of both 2me-sensitive antibodies and splenic pfcs in autumn but not in summer. during the secondary response, 2me-resistant antibodies were found in both seasons, but the number of pfcs was significantly reduced during summ ... | 1986 | 3514443 |
| immunocytochemical study of the hypothalamic magnocellular neurosecretory nuclei of the snake natrix maura and the turtle mauremys caspica. | an immunocytochemical study of the magnocellular neurosecretory nuclei was performed in the snake natrix maura and the turtle mauremys caspica by use of antisera against: (1) a mixture of both bovine neurophysins, (2) bovine oxytocin-neurophysin, (3) arginine vasotocin, and (4) mesotocin. arginine vasotocin- and mesotocin-immunoreactivities were localized in individual neurons of the supraoptic and paraventricular nuclei, with a distinct pattern of distribution in both species. the same cells ap ... | 1988 | 3409295 |
| lectin binding pattern in the testes of several tetrapode vertebrates. | the glycoconjugates of the testes of four species of vertebrates including amphibians (bufo calamita), reptiles (mauremys caspica), birds (columba livia) and mammals (mesocricetus auratus) were investigated by means of lectin histochemistry. spermatogonia of the animals studied were labelled by con a and wga. dba showed a specific affinity for the spermatogonia aal of the hamster indicating that dba might be an useful marker for this cell type. the acrosomes of the hamster spermatids were strong ... | 1991 | 1768726 |
| cytochrome p-450 mediated metabolism of progesterone by adrenal microsomes of pcb-treated and untreated barn owl (tyto alba) and marsh turtle (mauremys caspica) in comparison with the guinea-pig. | 1. significant differences between species were observed in the profile of steroids produced from progesterone by adrenal microsomes as well as in the effects elicited by aroclor 1254 on cytochrome p-450-mediated activities. 2. in the guinea-pig, the major metabolites were products of the corticosteroid pathway but products of the androgenic pathway were also detected; in the barn owl products of both pathways were also formed while in the marsh turtle only products of the corticosteroid pathway ... | 1991 | 1675970 |
| neural organization of the retina of the turtle mauremys caspica: a light microscope and golgi study. | the organization of the retina of the turtle species mauremys caspica, found in fresh water ponds of israel, has been examined by light microscopical techniques including examination of fresh wholemount retina, one micron blue-stained vertical sections and golgi-stained material. the anatomical findings on mauremys retina have been compared with those of the pseudemys retina (kolb, 1982) which is more commonly used for electrophysiological and neurochemical studies in the usa. the photoreceptors ... | 2011 | 3154788 |
| the distal forelimb musculature in aquatic and terrestrial turtles: phylogeny or environmental constraints? | we compared the muscular anatomy of the distal front limb in terrestrial and aquatic chelonians to test whether observed differences between the two groups are associated with their divergent lifestyles and locomotor modes. given the different use of the forelimb in the two environments (body support and propulsion on land vs. mainly propulsion in water) we expected that: (1) aquatic and terrestrial turtles would show differences in their muscular anatomy, with aquatic species having more indivi ... | 2008 | 19172731 |
| gastrointestinal helminths of the caspian turtle, mauremys caspica (testudines), from northern iran. | the caspian turtle (mauremys caspica) is a semi-aquatic and adaptable reptile. to date, there are no reports on the parasites of this turtle in iran. hence, the current survey was designed to prepare a list of the gastrointestinal helminth parasites of the caspian turtle in north iran. a total of 34 road-killed individuals (14 males and 20 females) were collected between july 2011 and october 2012 from the mazandaran province, iran. all parts of gastrointestinal were parasitologically scrutinize ... | 2016 | 27065600 |
| morphological and molecular characterisation of haemogregarina sp. (apicomplexa: adeleina: haemogregarinidae) from the blood of the caspian freshwater turtle mauremys caspica (gmelin) (geoemydidae) in iran. | to date, a number of species of haemogregarina have been described from different turtle hosts, mainly based on the morphology of the developmental stages detected in the host erythrocytes. the diversity and overlapping morphological features in the old and recent descriptions has led to considerable complications in the taxonomy of haemogregarina spp. in this study, different stages of maturity and developing gamonts of a putative new species of haemogregarina were detected in erythrocytes of t ... | 2016 | 27221004 |
| a morphological study of the principal and accessory abducens nuclei in the caspian terrapin (mauremys caspica). | the location of principal and accessory motoneurons and principal interneurons of the nucleus abducens was determined in the caspian terrapin (mauremys caspica) by means of horseradish peroxidase histochemical tracing. enzyme injections were made into the ipsilateral lateral rectus and retractor bulbi muscles and into the contralateral oculomotor nucleus. labeled principal abducens motoneurons formed a cluster of cells in the rhombencephalon, under the ivth ventricle and adjacent to the medial l ... | 1993 | 8431756 |
| complexity and scaling properties of amacrine, ganglion, horizontal, and bipolar cells in the turtle retina. | in the present study we have evaluated the complexity and scaling properties of the morphology of retinal neurons using fractal dimension as a quantitative parameter. we examined a large number of cells from pseudemys scripta and mauremys caspica turtles that had been labeled using golgi-impregnation techniques, intracellular injection of lucifer yellow followed by photooxidation, intracellular injection of rhodamine conjugated horseradish peroxidase, or intracellular injection of lucifer yellow ... | 1994 | 7529776 |
| pathological study of lesion caused by serpinema microcephalus (nematoda: camallanidae) in mauremys caspica caspica from north of iran. | serpinema microcephalus is nematoda from family camallanidae, which have a lot of pathogenesis species that harbored via many animals like fishes, reptiles and amphibians. epidemiological study in different regions and histopathological examination of intestinal parasitic infections caused by s. microcephalus are prerequisite to develop appropriate control strategies. this study aimed to describe the lesions caused by s. microcephalus from caspian turtles of north of iran. thirty-four adult turt ... | 2015 | 26688634 |
| light microscope study of the enzymatic activities of aspartate aminotransferase, gaba transaminase and acetylcholinesterase in the mesencephalic trigeminal nucleus neural complex of mauremys caspica. | the enzymatic activities of aspartate aminotransferase, gaba-transaminase and acetylcholinesterase were studied by means of histochemical methods in the mesencephalic trigeminal nucleus (mtn) neural complex of the turtle mauremys caspica. light microscope observations have demonstrated that mtn neurons have a positive reaction for these enzymes. | 1990 | 2379232 |
| anesthetic efficacy of ketamine-diazepam, ketamine-xylazine, and ketamine-acepromazine in caspian pond turtles (mauremys caspica). | the objective of this study was to assess the efficacy of different anesthetic drug combinations on the caspian pond turtles (mauremys caspica). | 2017 | 28458430 |
| a comparative study of inorganic elements in the blood of male and female caspian pond turtles (mauremys caspica) from the southern basin of the caspian sea. | due to their bioaccumulation and biomagnification pathways, inorganic elements can accumulate in high-level aquatic organisms in the food web. then, this species can be used to monitor the quality of the environment. blood concentration of nine inorganic elements, including possible toxic metals (an, cu, mn, se, as, ni, cd, pb, and hg), in 20 males and 20 females from eight different locations with high industry and agriculture activities in iran were evaluated in this work. additionally, size, ... | 2017 | 28918536 |
| metabolism of parathion and brain cholinesterase inhibition in aroclor 1254-treated and untreated caspian terrapin (mauremys caspica rivulata, emydidae, chelonia) in comparison with two species of wild birds. | the mean level of pcb residues in the liver of the caspian turtle collected in nature was 23 ppm, or approximately 20-fold greater than that detected in the two bird species tested. treatment of the turtles with aroclor 1254 resulted in a 30-fold increase in the level of pcb residues in the liver but did not cause any increase in the content of cytochrome p-450 and the desulfurase activity of this hemoprotein. the ki value for acetylcholinesterase inhibition by paraoxon in brain homogenate of th ... | 1983 | 6138207 |
| morphological correlations of hearing in the phylogenetic scale: mauremys caspica. | | 1989 | 2748670 |
| distribution of mucins in the mucosa of the digestive tract of reptiles: a histochemical study. | in the present study, the distribution and characteristics of mucins in the digestive tract of 3 reptiles (lacerta lepida, mauremys caspica and testudo graeca) are investigated. in the esophagus of testudo graeca, both the glands and the mucous cells of the surface epithelium contained sulphosialo-mucins. in lacerta lepida, esophageal mucous cells contained either-sialo-mucins or sulphosialo-mucins. the esophageal mucous cells of mauremys caspica contained acidic mucosubstances. the stomach of t ... | 1989 | 2472727 |
| ultrastructural peculiarities of the supraoptic nucleus of mauremys caspica (turtle): its evolutionary interest in reptiles. | the hypothalamic supraoptic nucleus (son) supposes an evolutionary achievement in the reptiles, zoological group in which this nucleus is first differentiated. its scarce development in the chelonian, subject of the present study, is related to their primitive brain pattern. the peculiar location and the topographical configuration of the son in the hypothalamus of the turtle mauremys caspica allows to evidence morphologically the successive steps in the evolutionary process from lower to higher ... | 1988 | 3189859 |
| [tunisian reptiles. iii. distribution and need for protection of terrestrial and fresh water turtles]. | the distribution and habitats in tunisia of the tortoise testudo graeca graeca and of the two turtles emys orbicularis and mauremys caspica leprosa are investigated throughout the country. the present low level of population density is recent; its causes are precised. the protection, more specially for the two first species, must be very efficient. | 2006 | 747452 |
| ultrastructure of the nephron of freshwater turtles, pseudemys scripta elegans and mauremys caspica. | the nephrons of the freshwater turtles pseudemys scripta elegans and mauremys caspica consist of renal corpuscle, neck segment, proximal tubule, intermediate segment, distal tubule and collecting duct. the renal corpuscle has large and scarce capillaries with clear and dark fenestrated endothelial cells containing some rod-shaped bodies, a thin filtration barrier and a well-developed mesangium, the cells of which show secretory, phagocytic and contractile features, and in m. caspica a cilium. th ... | 1987 | 3581151 |
| the intra-ocular portion of the optic nerve in the turtle mauremys caspica. | the cytoarchitecture of the intra-ocular optic nerve was investigated by light and electron microscopy. glial cells in the intra-ocular portion are disposed among the axons, either scattered or forming columns, and bordering the nervous parenchyma. astroglia forms the limiting glia that separates the optic nerve from the vitreous body, retina, choroid and sclera. indentations of choroid-scleral tissue are observed in the limiting glial sheet as well as an abundance of hemidesmosomes in the astro ... | 1987 | 3654350 |
| ventricular labyrinths of the ependyma adjacent to the hypothalamic paraventricular nucleus in the turtle mauremys caspica. | labyrinthic recesses projecting to the subependymal tissue have been observed in the ependyma of the iii ventricle in close relation to the neurons of the hypothalamic paraventricular nucleus in the turtle mauremys caspica. there seems to be evidence of a direct contact between the paraventricular nucleus neurons and the cerebrospinal fluid whose physiological significance is discussed in the present work. | 1986 | 3760552 |
| [contacts of the basal processes of the visual cone cells in the outer plexiform layer of the sensory membrane of the eyeball in turtles]. | in two tortoise (agrionemys horsfieldi gray, testudo graeca l.) and three turtle (emys orbicularis l., clemmys (mauremys) caspica gmel, tryonix sinensis wieg) species, contacts of basal processes (synaptic peduncles of the cone cells) have been studied electron microscopically. their ultrastructure and peculiarities in organization of specialized junctions between each other and with other neural elements are described. the interreceptory contacts revealed are considered to be of one of the gap ... | 1983 | 6661055 |
| ultrastructure of the calcareous layer eggshell of the turtle emys orbicularis (l.). preliminary study. | the calcareous layer of emys orbicularis eggshell was examined by scanning electron microscopy. the layer is composed of well distinguished shell units which consist of needle-like crystallites radiating outwards from the cores. the linear structures of the cores on the inner surface appear to be similar to those in the eggshell of mauremys caspica. on the inner surface of shell units of eggs with dead embryos there are flat, conical depressions. this surface in specimens from unfertilized eggs ... | 1997 | 9646702 |
| chromosomal damage in two species of aquatic turtles (emys orbicularis and mauremys caspica) inhabiting contaminated sites in azerbaijan. | the caspian region and specifically the apsheron peninsula of azerbaijan are known to be polluted with a variety of environmental contaminants. these complex mixtures of contaminants make risk assessment difficult. we used the flow cytometry method (fcm) and the micronucleus assay (mn) to assess chromosomal damage in aquatic turtles (emys orbicularis, the european pond turtle; and mauremys caspica, the caspian turtle) inhabiting contaminated wetlands in azerbaijan. evidence of genetic damage was ... | 2005 | 16220359 |
| haemogregarines from western palaearctic freshwater turtles (genera emys, mauremys) are conspecific with haemogregarina stepanowi danilewsky, 1885. | the majority of haemogregarina species have been based on the morphology of their erythrocytic stages and supposed strict host specificity. the quantity of species with a limited number of overlapping diagnostic traits has led to a considerable mess in haemogregarine taxonomy and significant synonymy. we analysed host specificity, intra- and interspecific variability, evolutionary relationships, and the distribution of the type species of the genus haemogregarina--h. stepanowi. the morphology of ... | 2014 | 24476992 |
| molecular and morphological characterization of a haemogregarine in the alligator snapping turtle, macrochelys temminckii (testudines: chelydridae). | a severely underweight alligator snapping turtle macrochelys temminckii troost in harlan, 1835, was found near tyler, texas, and taken to the caldwell zoo. blood films were submitted to texas a&m university, college station, texas, for morphological and molecular identification of haemogregarine-like inclusions in the red blood cells. intraerythrocytic haemogregarina sp. forms were found on microscopic examination at a parasitemia of <1 %. the morphology and morphometric data for the forms indic ... | 2017 | 27807618 |
| neural interactions between cone photoreceptors and horizontal cells in the turtle (mauremys caspica) retina. | horizontal cells and cone photoreceptors in the vertebrate retina are interconnected by a complex network of synapses leading to the generation of color-coded responses in chromaticity horizontal cells. a simple cascade model of excitatory feedforward and inhibitory feedback synapses had been suggested to underlie these observations. in this study, the photoresponses of cones and horizontal cells were recorded intracellularly from the turtle eyecup. three different approaches were adopted in ord ... | 2008 | 9456500 |
| effect of temperature on oxygen stores during aerobic diving in the freshwater turtle mauremys caspica leprosa. | oxygen stores available for aerobic diving were studied in the freshwater turtle (mauremys caspica leprosa) at three constant body temperatures (15 degrees, 25 degrees, and 35 degrees c) and during the thermal transient (30 degrees-15 degrees c) induced by immersion in cold water. the term "aerobic dive limit" has been defined as the maximal duration of the dive before lactate increases. this increase occurs when a critical po2 value is reached, and it is well characterized at lung level by a sh ... | 2013 | 9231371 |
| mercury, lead, and cadmium in tissues of the caspian pond turtle (mauremys caspica) from the southern basin of caspian sea. | concentrations of cadmium, lead, and mercury were measured in different tissues (liver, muscle, and shell) of 60 caspian pond turtles collected from tajan and shiroud rivers, southern basin of the caspian sea. based on the results, different tissues showed different capacities for accumulating trace elements. the general trend of metals accumulation was: liver > shell > muscle. results also showed that accumulation of these elements was not significantly different between sex and river in turtle ... | 2017 | 26686855 |
| assessment trace elements concentrations in tissues in caspian pond turtle (mauremys caspica) from golestan province, iran. | concentrations of cadmium, lead, zinc, and copper were measured in different organs and tissues of 15 caspian pond turtle (mauremys caspica) collected from gharehsu river, golestan province, iran in june and july 2012. mean concentrations (dry weight) of zinc and copper were 66.9 and 6.7µgg(-1) in liver, 147 and 3.4µgg(-1) in heart, 93.2 and 4.9µgg(-1) in shell, and finally 150.7 and 4.5µgg(-1) in muscle, respectively. mean concentrations of cadmium and lead were 5.8 and 32.4µgg(-1) in liver, 2. ... | 2014 | 24507145 |
| light adaptation and color opponency of horizontal cells in the turtle retina. | chromaticity-type (c-type) horizontal cells of the turtle retina receive antagonistic inputs from cones of different spectral types, and therefore their response to background illumination is expected to reflect light adaptation of the cones and the interactions between their antagonistic inputs. our goal was to study the behavior of c-type horizontal cells during background illumination and to evaluate the role of wavelength in background adaptation. the photoresponses of c-type horizontal cell ... | 2014 | 14658772 |
| in vitro proliferation of blood, spleen and thymus leukocytes from the turtle mauremys caspica. | cell-mediated immune responses is commonly evaluated by cell proliferation assays. mitogens are known to induce a vigorous proliferative response in lymphoid cells from mammals but relatively fewer studies have investigated mitogen-mediated lymphoproliferation in non-mammalian animals. in the present work, we incubated spleen, thymus and blood leukocytes with phytohaemagglutinin (pha), concanavalin a (con a), lipopolysaccharide (lps) and pokeweed mitogen (pwm), by different times of incubation ( ... | 2003 | 12643977 |
| turtle c-type horizontal cells act as push-pull devices. | chromaticity (c-type) horizontal cells in the retina of cold-blooded vertebrates receive antagonistic inputs from cone photoreceptors of different spectral types leading to color opponency. the relative contribution of each spectral type of cones can be selectively altered by chromatic background illumination. therefore, the spectral properties of c-type horizontal cells are expected to change when the intensity and color of ambient illumination are altered. in this study, we investigated the ef ... | 2008 | 12020079 |
| the effect of the seasonal cycle on the splenic leukocyte functions in the turtle mauremys caspica. | the reptile immune system is strikingly affected by seasonal variations, which induce changes in the structure of the lymphoid organs and in the function of the leukocytes. the aim of this work is to study several functions of splenic leukocytes from the turtle mauremys caspica along its seasonal cycle. the functions assayed were adherence to substrate, mobility directed to a chemoattractant gradient (chemotaxis), lymphoproliferative response to mitogens, antibody-dependent cellular cytotoxicity ... | 2006 | 11517451 |
| the immune response of thymic cells from the turtle mauremys caspica. | in the present work several known mammalian leukocyte functions such as directed mobility, proliferative response to mitogens, antibody-dependent cellular cytotoxicity (adcc) and natural killer (nk)-mediated cytotoxicity were studied in female and male mauremys caspica turtles. since the reptilian thymus shows seasonal variations in its structure, we have performed all the assays along the seasonal cycle. our results show that thymic cells from m. caspica are able to migrate through a chemo-attr ... | 2001 | 11352102 |
| seasonal changes in peripheral blood leukocyte functions of the turtle mauremys caspica and their relationship with corticosterone, 17-beta-estradiol and testosterone serum levels. | we have studied the most representative functions of lymphocytes such as adherence to substrate, mobility directed to a chemoattractant gradient (chemotaxis), proliferative response to mitogens and antibody-dependent cellular cytotoxicity (adcc), as well as natural killer (nk) activity in peripheral blood cells from the turtle mauremys caspica, and the seasonal changes of these functions in both female and male animals. the plasma levels of steroid hormones were determined to study their relatio ... | 2000 | 11068064 |
| uv-sensitive input to horizontal cells in the turtle retina. | microspectrophotometry, electroretinography and behavioural studies have indicated that ultraviolet (uv) light contributes to functional vision in various vertebrate species. based on behavioural evidence, this was also suggested for turtle vision. in order to reveal the interactions underlying detection of uv light in the distal retina, we recorded intracellularly the photoresponses of cones and horizontal cells in retinas of pseudemys scripta elegans and mauremys caspica and calculated the act ... | 1998 | 9751127 |
| comparative immunohistochemical study of the gastroenteropancreatic endocrine system of three reptiles. | the gastroenteropancreatic (gep) endocrine system of three reptiles, testudo graeca, mauremys caspica, and lacerta lepida, was investigated by means of immunocytochemistry. single and double immunostaining methods have demonstrated immunoreactivity for insulin, glucagon, pancreatic polypeptide (pp), somatostatin, serotonin, and peptide tyrosine tyrosine (pyy) in endocrine cells of the pancreas of the reptiles studied. islet-like structures with insulin-immunoreactive (ir) cells surrounded by glu ... | 1989 | 2574125 |
| comparative study on the endocrine cells in the pancreas of mauremys caspica (chelonia) in summer and winter. | four endocrine cell types were identified using peroxidase-antiperoxidase (pap) technique and ultrastructurally characterized in the pancreas of mauremys caspica in both winter and summer. in winter, insulin-immunoreactive cells were more abundant and the cell groups larger in the splenic than in the duodenal region, whereas in summer, medium or small cell groups were evenly distributed. glucagon- and somatostatin-immunoreactive cells were found throughout the gland; they were more numerous in t ... | 1989 | 2676701 |
| ultrastructural changes in the thymus of the turtle mauremys caspica in relation to the seasonal cycle. | changes in the ultrastructure of the thymus of the turtle mauremys caspica, with special reference to its non-lymphoid components, were studied in relation to the seasonal cycle. the thymic cortex contains framework-forming epithelial-reticular cells and free macrophages, while the medulla includes, in addition, mature and presumptive pro-interdigitating cells. the ultrastructural features of these cells are generally similar to those described for non-lymphoid components of the mammalian thymus ... | 1989 | 2713893 |
| immunocytochemical localization of serotonin in the reptilian lung. | the distribution of serotonin-immunoreactive cells in the lung of 4 species of reptiles was investigated. serotonin-containing cells were found forming groups in the interconnecting septa in all 4 species studied, and also as solitary cells in testudo graeca and mauremys caspica. serotonin-containing cells were also localized in the intramural ganglia of pseudemys scripta elegans and testudo graeca. the present study confirms that serotonin is widely distributed in the lung of vertebrates. | 1987 | 3301000 |
| distribution of galanin-like immunoreactivity in the brain of the turtle mauremys caspica. | galanin is a brain-gut peptide present in the central nervous system of fish, amphibians, birds, and mammals. for comparative studies among vertebrates, the distribution of galanin in the brain of reptiles has been investigated. we studied the localization of galanin-like-immunoreactive perikarya and nerve fibers in the brain of the turtle mauremys caspica by using an antiserum against porcine galanin. in the telencephalon, few immunoreactive perikarya were seen in the amygdaloid complex. the di ... | 1994 | 7531723 |
| the action spectra of cone photoreceptors in the turtle (mauremys caspica) retina. | cone photoreceptors in the turtle retina are involved in intricate neuronal interactions with other retinal neurons that modify the responses of the cones to photons absorbed in their outer segments. therefore, the action spectra of cones strongly depend upon the conditions of measurements. this study describes an attempt to derive the action spectra of turtle cones which are the least distorted by neuronal interactions. to achieve this goal, the photoresponses of cones and horizontal cells were ... | 2008 | 8003451 |
| changes in the thymus and spleen of the turtle mauremys caspica after testosterone injection: a morphometric study. | to confirm a possible role of sex hormones in governing the seasonal variations affecting the reptilian lymphoid organs, a morphometric analysis was carried out on the thymus and spleen of turtles, mauremys caspica, intraperitoneally injected with a single dose of testosterone propionate (tp) at the third week of june when physiological levels of testosterone are low. at 4 and 6 weeks, control turtles show an apparent lymphocyte mobilization both from thymus and spleen with a decrease in the per ... | 2013 | 1499836 |
| testosterone induces lymphopenia in turtles. | owing to the possible role of sex steroids in the immune-neuroendocrine interactions found in lower vertebrates, we attempted to delineate the effect of testosterone propionate on peripheral blood (pb) and the lymphoid organs of the turtle mauremys caspica. a single intraperitoneal injection of 200 micrograms/g body weight produced thymic involution and intense lymphopenia in the spleen and, less severely, in the pb compartment. it is suggested that lymphocyte redistribution may occur among the ... | 1991 | 1866894 |
| ganglionic character of mesencephalic trigeminal neurons in the turtle mauremys caspica. | a study of the morphology of the mesencephalic trigeminal neurons and their arrangement in the optic tectum has been made in the turtle mauremys caspica employing the cajal reduced silver method. the ganglionic features of its neurons suggest that the mesencephalic trigeminal nucleus (mtn) is a diffuse sensory ganglion located in the central nervous system. the different distribution of two cell populations, probably as a result of a distinct embryonic origin of their elements, and the atypical ... | 1984 | 6507902 |
| piretanide induced changes on transepithelial potential difference in the intestine of mauremys caspica. | | 1984 | 6484285 |
| interdigitating cells in the thymus of the turtle mauremys caspica. possible relationships to macrophages. | interdigitating cells are non-lymphoid elements in the thymus and peripheral, secondary lymphoid organs of higher vertebrates. their origin and functional significance are a matter of controversy. in the present investigation we analyze, for the first time, the nature of presumptive interdigitating cells of the thymus of an ectothermic vertebrate, the turtle mauremys caspica. this model is specially useful because of the seasonal variations that affect the reptilian lymphoid organs. immature pro ... | 1984 | 6509513 |
| effect of bicarbonate and furosemide on chloride accumulation by the intestine of the freshwater turtle mauremys caspica. | the influence of hco3- on cl- absorption by the intestine of the freshwater turtle mauremys caspica has been studied. na+, k+ and cl- intracellular concentrations together with transepithelial potential difference were measured. in hco3--free medium, transepithelial potential difference was serosal positive. a reversal in the sign of the transepithelial potential difference was observed in hco3- medium. a subsequent addition of 10(-3) m furosemide to hco3- medium blocked, at least partially, thi ... | 1983 | 6622803 |
| sodium, potassium and chloride intracellular concentrations in the intestine of the freshwater turtle mauremys caspica. | sodium, potassium and chloride intracellular concentrations were measured. sodium replacement from the bathing medium induced a significant decrease in chloride intracellular concentration. conversely, chloride replacement from the bathing medium induced a significant decrease in sodium intracellular concentration. these results suggest the existence of a coupled nacl transport system. the presence of 10(-3) m ouabain in the bathing medium increased na+ intracellular concentration while decreasi ... | 1983 | 6622802 |
| ultrastructure of splenic white pulp of the turtle, mauremys caspica. | the ultrastructure of splenic tissue of non-immunized turtles, mauremys cas[pica, shows two areas, namely, the white pulp which is lymphoid in nature, and the red pulp which is formed by cell cords and sinusoids, between both areas there is always a marginal zone with gaps through which cells leak. in the white pulp, there are two blood vessel types; one with muscled walls, and the other showing thinner walls sheathed by reticular cells, reticular cells constitute a network where there occur den ... | 1981 | 7296658 |
| altered structures in the cytoplasm of the ependymal cells next to the periventricular nucleus of the turtle mauremys caspica. | in the apical cytoplasm of some ependymal cells of the hypothalamic periventricular nucleus of the turtle mauremys caspica large amount of cell structures of difficult diagnose are found. their morphology is variable seeming to correspond to cell organelles in a process of degeneration, characteristic feature of the high metabolic activity in the ventricular barrier. their possible physiological significance is discussed in the present work. | 1986 | 3033066 |
| apical membrane potentials and intracellular potassium and sodium activities in the gallbladder of the freshwater turtle mauremys caspica. | open-tip and liquid ion-exchanger microelectrodes were used to measure transapical membrane potential (va), fractional voltage ratio (fa) and intracellular sodium and potassium activities (aina, aik) in mauremys caspica gallbladder under open circuit conditions. the average values (+/- sem) for va and fa were -32 +/- 3 and 0.20 +/- 0.03 mv respectively. aina and aik were, respectively, 17 +/- 4 and 82 +/- 7 mm. these results suggest that the mechanisms of na+ and k+ transport in this tissue are ... | 1986 | 2876809 |
| furosemide inhibits chloride influx into the intestine of the freshwater turtle mauremys caspica. | | 1985 | 4001540 |
| seasonal changes in the thymus and spleen of the turtle, mauremys caspica. a morphometrical, light microscopical study. | mauremys caspica has been used to analyze morphological changes which affect lymphoid organs (thymus and spleen) throughout the year related to annual variations of circulating steroid hormones. both organs undergo seasonal variations which, however, differentially affect their distinct compartments (cortex and medulla in the thymus; pals and pels in the splenic white pulp). the greatest thymic involution occurs in summer, with some recovery at the beginning of autumn and a slow decrease through ... | 1985 | 3910485 |
| similarity between cytoplasmic inclusions in the paraventricular hypothalamic nucleus neurons of the turtle mauremys caspica and the cytoplasmic structures as reaction to viral infections (hepatitis) and sida ultrastructural tracers. | two types of "inclusions" observed in the neurons of the hypothalamic paraventricular nucleus of the turtle mauremys caspica, "tubular systems" and "fingerprint-like" structures, may be added to the inventory of those described in apparently normal neurons. despite their enigmatic significance, we are inclined to think that they could be a morphological expression of viral diseases in the neuron cytoplasm. these structures have a striking similarity with those observed on pathological cells (hep ... | 1985 | 3003185 |
| [notes on the reptiles of tunisia. v. biometric characteristics of mauremys caspica leprosa (schweigger, 1812) (reptilia: emydidae)]. | this morphological study is based on 45 specimens of mauremys caspica leprosa (reptilia: emydidae) sampled in northern and central tunisia. a first principal component analysis of 9 variables: 8 measurements of the shell and the weight in life, allow to define a factor "size"; a second analysis of these variables divided by the size make obvious a factor "shape". in the plane of these two factors, our specimens may be classified into 6 groups from the hatchling stage to the large adults; in addi ... | 1978 | 756700 |